﻿/*
** 2001 September 15
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains routines used for analyzing expressions and
** for generating VDBE code that evaluates expressions in SQLite.
**
** $Id: expr.c,v 1.257 2006/03/17 13:56:34 drh Exp $
*/
#include "sqliteInt.h"

/*
** Return the 'affinity' of the expression pExpr if any.
**
** If pExpr is a column, a reference to a column via an 'AS' alias,
** or a sub-select with a column as the return value, then the
** affinity of that column is returned. Otherwise, 0x00 is returned,
** indicating no affinity for the expression.
**
** i.e. the WHERE clause expresssions in the following statements all
** have an affinity:
**
** CREATE TABLE t1(a);
** SELECT * FROM t1 WHERE a;
** SELECT a AS b FROM t1 WHERE b;
** SELECT * FROM t1 WHERE (select a from t1);
*/
char sqlite3ExprAffinity(Expr *pExpr){
  int op = pExpr->op;
  if( op==TK_AS ){
    return sqlite3ExprAffinity(pExpr->pLeft);
  }
  if( op==TK_SELECT ){
    return sqlite3ExprAffinity(pExpr->pSelect->pEList->a[0].pExpr);
  }
#ifndef SQLITE_OMIT_CAST
  if( op==TK_CAST ){
    return sqlite3AffinityType(&pExpr->token);
  }
#endif
  return pExpr->affinity;
}

/*
** Return the default collation sequence for the expression pExpr. If
** there is no default collation type, return 0.
*/
/* CollSeq *sqlite3ExprCollSeq(Parse *pParse, Expr *pExpr){ */
/*   CollSeq *pColl = 0; */
/*   if( pExpr ){ */
/*     pColl = pExpr->pColl; */
/*     if( (pExpr->op==TK_AS || pExpr->op==TK_CAST) && !pColl ){ */
/*       return sqlite3ExprCollSeq(pParse, pExpr->pLeft); */
/*     } */
/*   } */
/*   if( sqlite3CheckCollSeq(pParse, pColl) ){ */
/*     pColl = 0; */
/*   } */
/*   return pColl; */
/* } */

/*
** pExpr is an operand of a comparison operator.  aff2 is the
** type affinity of the other operand.  This routine returns the
** type affinity that should be used for the comparison operator.
*/
char sqlite3CompareAffinity(Expr *pExpr, char aff2){
  char aff1 = sqlite3ExprAffinity(pExpr);
  if( aff1 && aff2 ){
    /* Both sides of the comparison are columns. If one has numeric
    ** affinity, use that. Otherwise use no affinity.
    */
    if( sqlite3IsNumericAffinity(aff1) || sqlite3IsNumericAffinity(aff2) ){
      return SQLITE_AFF_NUMERIC;
    }else{
      return SQLITE_AFF_NONE;
    }
  }else if( !aff1 && !aff2 ){
    /* Neither side of the comparison is a column.  Compare the
    ** results directly.
    */
    return SQLITE_AFF_NONE;
  }else{
    /* One side is a column, the other is not. Use the columns affinity. */
    assert( aff1==0 || aff2==0 );
    return (aff1 + aff2);
  }
}

/*
** pExpr is a comparison operator.  Return the type affinity that should
** be applied to both operands prior to doing the comparison.
*/
static char comparisonAffinity(Expr *pExpr){
  char aff;
  assert( pExpr->op==TK_EQ || pExpr->op==TK_IN || pExpr->op==TK_LT ||
          pExpr->op==TK_GT || pExpr->op==TK_GE || pExpr->op==TK_LE ||
          pExpr->op==TK_NE );
  assert( pExpr->pLeft );
  aff = sqlite3ExprAffinity(pExpr->pLeft);
  if( pExpr->pRight ){
    aff = sqlite3CompareAffinity(pExpr->pRight, aff);
  }
  else if( pExpr->pSelect ){
    aff = sqlite3CompareAffinity(pExpr->pSelect->pEList->a[0].pExpr, aff);
  }
  else if( !aff ){
    aff = SQLITE_AFF_NUMERIC;
  }
  return aff;
}

/*
** pExpr is a comparison expression, eg. '=', '<', IN(...) etc.
** idx_affinity is the affinity of an indexed column. Return true
** if the index with affinity idx_affinity may be used to implement
** the comparison in pExpr.
*/
/*int sqlite3IndexAffinityOk(Expr *pExpr, char idx_affinity){
  char aff = comparisonAffinity(pExpr);
  switch( aff ){
    case SQLITE_AFF_NONE:
      return 1;
    case SQLITE_AFF_TEXT:
      return idx_affinity==SQLITE_AFF_TEXT;
    default:
      return sqlite3IsNumericAffinity(idx_affinity);
  }
}*/

/*
** Return the P1 value that should be used for a binary comparison
** opcode (OP_Eq, OP_Ge etc.) used to compare pExpr1 and pExpr2.
** If jumpIfNull is true, then set the low byte of the returned
** P1 value to tell the opcode to jump if either expression
** evaluates to NULL.
*/
/*static int binaryCompareP1(Expr *pExpr1, Expr *pExpr2, int jumpIfNull){
  char aff = sqlite3ExprAffinity(pExpr2);
  return ((int)sqlite3CompareAffinity(pExpr1, aff))+(jumpIfNull?0x100:0);
}*/

/*
** Return a pointer to the collation sequence that should be used by
** a binary comparison operator comparing pLeft and pRight.
**
** If the left hand expression has a collating sequence type, then it is
** used. Otherwise the collation sequence for the right hand expression
** is used, or the default (BINARY) if neither expression has a collating
** type.
*/
/* static CollSeq* binaryCompareCollSeq(Parse *pParse, Expr *pLeft, Expr *pRight){ */
/*   CollSeq *pColl = sqlite3ExprCollSeq(pParse, pLeft); */
/*   if( !pColl ){ */
/*     pColl = sqlite3ExprCollSeq(pParse, pRight); */
/*   } */
/*   return pColl; */
/* } */

/*
** Generate code for a comparison operator.
*/
/* static int codeCompare( */
/*   Parse *pParse,    /1* The parsing (and code generating) context *1/ */
/*   Expr *pLeft,      /1* The left operand *1/ */
/*   Expr *pRight,     /1* The right operand *1/ */
/*   int opcode,       /1* The comparison opcode *1/ */
/*   int dest,         /1* Jump here if true.  *1/ */
/*   int jumpIfNull    /1* If true, jump if either operand is NULL *1/ */
/* ){ */
/*   int p1 = binaryCompareP1(pLeft, pRight, jumpIfNull); */
/*   CollSeq *p3 = binaryCompareCollSeq(pParse, pLeft, pRight); */
/*   return sqlite3VdbeOp3(pParse->pVdbe, opcode, p1, dest, (void*)p3, P3_COLLSEQ); */
/* } */

/*
** Construct a new expression node and return a pointer to it.  Memory
** for this node is obtained from sqliteMalloc().  The calling function
** is responsible for making sure the node eventually gets freed.
*/
Expr *sqlite3Expr(int op, Expr *pLeft, Expr *pRight, const Token *pToken){
  Expr *pNew;
  pNew = sqliteMalloc( sizeof(Expr) );
  if( pNew==0 ){
    /* When malloc fails, delete pLeft and pRight. Expressions passed to
    ** this function must always be allocated with sqlite3Expr() for this
    ** reason.
    */
    sqlite3ExprDelete(pLeft);
    sqlite3ExprDelete(pRight);
    return 0;
  }
  pNew->op = op;
  pNew->pLeft = pLeft;
  pNew->pRight = pRight;
  pNew->pParent = NULL;

  if (pLeft) {
      pLeft->pParent = pNew;
  }

  if (pRight) {
      pRight->pParent = pNew;
  }

  pNew->iAgg = -1;
  if( pToken ){
    assert( pToken->dyn==0 );
    pNew->span = pNew->token = *pToken;
  }else if( pLeft && pRight ){
    sqlite3ExprSpan(pNew, &pLeft->span, &pRight->span);
  }
  return pNew;
}

/*
** When doing a nested parse, you can include terms in an expression
** that look like this:   #0 #1 #2 ...  These terms refer to elements
** on the stack.  "#0" means the top of the stack.
** "#1" means the next down on the stack.  And so forth.
**
** This routine is called by the parser to deal with on of those terms.
** It immediately generates code to store the value in a memory location.
** The returns an expression that will code to extract the value from
** that memory location as needed.
*/
Expr *sqlite3RegisterExpr(Parse *pParse, Token *pToken){
  /* Vdbe *v = pParse->pVdbe; */
  /* Expr *p; */
  /* int depth; */
  /* if( pParse->nested==0 ){ */
  /*   sqlite3ErrorMsg(pParse, "near \"%T\": syntax error", pToken); */
  /*   return 0; */
  /* } */
  /* if( v==0 ) return 0; */
  /* p = sqlite3Expr(TK_REGISTER, 0, 0, pToken); */
  /* if( p==0 ){ */
  /*   return 0;  /1* Malloc failed *1/ */
  /* } */
  /* depth = atoi((char*)&pToken->z[1]); */
  /* p->iTable = pParse->nMem++; */
  /* sqlite3VdbeAddOp(v, OP_Dup, depth, 0); */
  /* sqlite3VdbeAddOp(v, OP_MemStore, p->iTable, 1); */
  /* return p; */
}

/*
** Join two expressions using an AND operator.  If either expression is
** NULL, then just return the other expression.
*/
Expr *sqlite3ExprAnd(Expr *pLeft, Expr *pRight){
  if( pLeft==0 ){
    return pRight;
  }else if( pRight==0 ){
    return pLeft;
  }else{
    return sqlite3Expr(TK_AND, pLeft, pRight, 0);
  }
}

/*
** Set the Expr.span field of the given expression to span all
** text between the two given tokens.
*/
void sqlite3ExprSpan(Expr *pExpr, Token *pLeft, Token *pRight){
  assert( pRight!=0 );
  assert( pLeft!=0 );
  if( !sqlite3MallocFailed() && pRight->z && pLeft->z ){
    assert( pLeft->dyn==0 || pLeft->z[pLeft->n]==0 );
    if( pLeft->dyn==0 && pRight->dyn==0 ){
      pExpr->span.z = pLeft->z;
      pExpr->span.n = pRight->n + (pRight->z - pLeft->z);
    }else{
      pExpr->span.z = 0;
    }
  }
}

/*
** Construct a new expression node for a function with multiple
** arguments.
*/
Expr *sqlite3ExprFunction(ExprList *pList, Token *pToken){
    Expr *pNew;
    assert( pToken );
    pNew = sqliteMalloc( sizeof(Expr) );
    if( pNew==0 ){
        sqlite3ExprListDelete(pList); /* Avoid leaking memory when malloc fails */
        return 0;
    }
    pNew->op = TK_FUNCTION;
    pNew->pList = pList;
    assert( pToken->dyn==0 );
    pNew->token = *pToken;
    pNew->span = pNew->token;
    return pNew;
}

Expr *sqlite3ExprLikeOp(ExprList *pList, Token *pToken) {
    Expr *pNew;
    assert( pToken );
    pNew = sqliteMalloc( sizeof(Expr) );
    if( pNew==0 ){
        sqlite3ExprListDelete(pList); /* Avoid leaking memory when malloc fails */
        return 0;
    }
    pNew->op = TK_LIKE_KW;
    pNew->pList = pList;
    assert( pToken->dyn==0 );
    pNew->token = *pToken;
    pNew->span = pNew->token;
    return pNew;

}

/*
** Assign a variable number to an expression that encodes a wildcard
** in the original SQL statement.
**
** Wildcards consisting of a single "?" are assigned the next sequential
** variable number.
**
** Wildcards of the form "?nnn" are assigned the number "nnn".  We make
** sure "nnn" is not too be to avoid a denial of service attack when
** the SQL statement comes from an external source.
**
** Wildcards of the form ":aaa" or "$aaa" are assigned the same number
** as the previous instance of the same wildcard.  Or if this is the first
** instance of the wildcard, the next sequenial variable number is
** assigned.
*/
void sqlite3ExprAssignVarNumber(Parse *pParse, Expr *pExpr){
  /* Token *pToken; */
  /* if( pExpr==0 ) return; */
  /* pToken = &pExpr->token; */
  /* assert( pToken->n>=1 ); */
  /* assert( pToken->z!=0 ); */
  /* assert( pToken->z[0]!=0 ); */
  /* if( pToken->n==1 ){ */
  /*   /1* Wildcard of the form "?".  Assign the next variable number *1/ */
  /*   pExpr->iTable = ++pParse->nVar; */
  /* }else if( pToken->z[0]=='?' ){ */
  /*   /1* Wildcard of the form "?nnn".  Convert "nnn" to an integer and */
  /*   ** use it as the variable number *1/ */
  /*   int i; */
  /*   pExpr->iTable = i = atoi((char*)&pToken->z[1]); */
  /*   if( i<1 || i>SQLITE_MAX_VARIABLE_NUMBER ){ */
  /*     sqlite3ErrorMsg(pParse, "variable number must be between ?1 and ?%d", */
  /*         SQLITE_MAX_VARIABLE_NUMBER); */
  /*   } */
  /*   if( i>pParse->nVar ){ */
  /*     pParse->nVar = i; */
  /*   } */
  /* }else{ */
  /*   /1* Wildcards of the form ":aaa" or "$aaa".  Reuse the same variable */
  /*   ** number as the prior appearance of the same name, or if the name */
  /*   ** has never appeared before, reuse the same variable number */
  /*   *1/ */
  /*   int i, n; */
  /*   n = pToken->n; */
  /*   for(i=0; i<pParse->nVarExpr; i++){ */
  /*     Expr *pE; */
  /*     if( (pE = pParse->apVarExpr[i])!=0 */
  /*         && pE->token.n==n */
  /*         && memcmp(pE->token.z, pToken->z, n)==0 ){ */
  /*       pExpr->iTable = pE->iTable; */
  /*       break; */
  /*     } */
  /*   } */
  /*   if( i>=pParse->nVarExpr ){ */
  /*     pExpr->iTable = ++pParse->nVar; */
  /*     if( pParse->nVarExpr>=pParse->nVarExprAlloc-1 ){ */
  /*       pParse->nVarExprAlloc += pParse->nVarExprAlloc + 10; */
  /*       sqliteReallocOrFree((void**)&pParse->apVarExpr, */
  /*                      pParse->nVarExprAlloc*sizeof(pParse->apVarExpr[0]) ); */
  /*     } */
  /*     if( !sqlite3MallocFailed() ){ */
  /*       assert( pParse->apVarExpr!=0 ); */
  /*       pParse->apVarExpr[pParse->nVarExpr++] = pExpr; */
  /*     } */
  /*   } */
  /* } */
}

/*
** Recursively delete an expression tree.
*/
void sqlite3ExprDelete(Expr *p){
  if( p==0 ) return;
  if( p->span.dyn ) sqliteFree((char*)p->span.z);
  if( p->token.dyn ) sqliteFree((char*)p->token.z);
  sqlite3ExprDelete(p->pLeft);
  sqlite3ExprDelete(p->pRight);
  sqlite3ExprListDelete(p->pList);
  sqlite3SelectDelete(p->pSelect);
  sqliteFree(p);
}

/*
** The Expr.token field might be a string literal that is quoted.
** If so, remove the quotation marks.
*/
/*void sqlite3DequoteExpr(Expr *p){
  if( ExprHasAnyProperty(p, EP_Dequoted) ){
    return;
  }
  ExprSetProperty(p, EP_Dequoted);
  if( p->token.dyn==0 ){
    sqlite3TokenCopy(&p->token, &p->token);
  }
  sqlite3Dequote((char*)p->token.z);
}*/


/*
** The following group of routines make deep copies of expressions,
** expression lists, ID lists, and select statements.  The copies can
** be deleted (by being passed to their respective ...Delete() routines)
** without effecting the originals.
**
** The expression list, ID, and source lists return by sqlite3ExprListDup(),
** sqlite3IdListDup(), and sqlite3SrcListDup() can not be further expanded
** by subsequent calls to sqlite*ListAppend() routines.
**
** Any tables that the SrcList might point to are not duplicated.
*/
Expr *sqlite3ExprDup(Expr *p){
  Expr *pNew;
  if( p==0 ) return 0;
  pNew = sqliteMallocRaw( sizeof(*p) );
  if( pNew==0 ) return 0;
  memcpy(pNew, p, sizeof(*pNew));
  if( p->token.z!=0 ){
    pNew->token.z = (u8*)sqliteStrNDup((char*)p->token.z, p->token.n);
    pNew->token.dyn = 1;
  }else{
    assert( pNew->token.z==0 );
  }
  pNew->span.z = 0;
  pNew->pLeft = sqlite3ExprDup(p->pLeft);
  pNew->pRight = sqlite3ExprDup(p->pRight);
  pNew->pList = sqlite3ExprListDup(p->pList);
  pNew->pSelect = sqlite3SelectDup(p->pSelect);
  pNew->pTab = p->pTab;
  return pNew;
}
void sqlite3TokenCopy(Token *pTo, Token *pFrom){
  if( pTo->dyn ) sqliteFree((char*)pTo->z);
  if( pFrom->z ){
    pTo->n = pFrom->n;
    pTo->z = (u8*)sqliteStrNDup((char*)pFrom->z, pFrom->n);
    pTo->dyn = 1;
  }else{
    pTo->z = 0;
  }
}
ExprList *sqlite3ExprListDup(ExprList *p){
  ExprList *pNew;
  struct ExprList_item *pItem, *pOldItem;
  int i;
  if( p==0 ) return 0;
  pNew = sqliteMalloc( sizeof(*pNew) );
  if( pNew==0 ) return 0;
  pNew->nExpr = pNew->nAlloc = p->nExpr;
  pNew->a = pItem = sqliteMalloc( p->nExpr*sizeof(p->a[0]) );
  if( pItem==0 ){
    sqliteFree(pNew);
    return 0;
  }
  pOldItem = p->a;
  for(i=0; i<p->nExpr; i++, pItem++, pOldItem++){
    Expr *pNewExpr, *pOldExpr;
    pItem->pExpr = pNewExpr = sqlite3ExprDup(pOldExpr = pOldItem->pExpr);
    if( pOldExpr->span.z!=0 && pNewExpr ){
      /* Always make a copy of the span for top-level expressions in the
      ** expression list.  The logic in SELECT processing that determines
      ** the names of columns in the result set needs this information */
      sqlite3TokenCopy(&pNewExpr->span, &pOldExpr->span);
    }
    assert( pNewExpr==0 || pNewExpr->span.z!=0
            || pOldExpr->span.z==0
            || sqlite3MallocFailed() );
    pItem->zName = sqliteStrDup(pOldItem->zName);
    pItem->sortOrder = pOldItem->sortOrder;
    pItem->isAgg = pOldItem->isAgg;
    pItem->done = 0;
  }
  return pNew;
}

/*
** If cursors, triggers, views and subqueries are all omitted from
** the build, then none of the following routines, except for
** sqlite3SelectDup(), can be called. sqlite3SelectDup() is sometimes
** called with a NULL argument.
*/
#if !defined(SQLITE_OMIT_VIEW) || !defined(SQLITE_OMIT_TRIGGER) \
 || !defined(SQLITE_OMIT_SUBQUERY)
SrcList *sqlite3SrcListDup(SrcList *p){
  SrcList *pNew;
  int i;
  int nByte;
  if( p==0 ) return 0;
  nByte = sizeof(*p) + (p->nSrc>0 ? sizeof(p->a[0]) * (p->nSrc-1) : 0);
  pNew = sqliteMallocRaw( nByte );
  if( pNew==0 ) return 0;
  pNew->nSrc = pNew->nAlloc = p->nSrc;
  for(i=0; i<p->nSrc; i++){
    struct SrcList_item *pNewItem = &pNew->a[i];
    struct SrcList_item *pOldItem = &p->a[i];
    Table *pTab;
    pNewItem->zDatabase = sqliteStrDup(pOldItem->zDatabase);
    pNewItem->zName = sqliteStrDup(pOldItem->zName);
    pNewItem->zAlias = sqliteStrDup(pOldItem->zAlias);
    pNewItem->jointype = pOldItem->jointype;
    pNewItem->iCursor = pOldItem->iCursor;
    pNewItem->isPopulated = pOldItem->isPopulated;
    pTab = pNewItem->pTab = pOldItem->pTab;
    if( pTab ){
      pTab->nRef++;
    }
    pNewItem->pSelect = sqlite3SelectDup(pOldItem->pSelect);
    pNewItem->pOn = sqlite3ExprDup(pOldItem->pOn);
    pNewItem->pUsing = sqlite3IdListDup(pOldItem->pUsing);
    pNewItem->colUsed = pOldItem->colUsed;
  }
  return pNew;
}
IdList *sqlite3IdListDup(IdList *p){
  IdList *pNew;
  int i;
  if( p==0 ) return 0;
  pNew = sqliteMallocRaw( sizeof(*pNew) );
  if( pNew==0 ) return 0;
  pNew->nId = pNew->nAlloc = p->nId;
  pNew->a = sqliteMallocRaw( p->nId*sizeof(p->a[0]) );
  if( pNew->a==0 ){
    sqliteFree(pNew);
    return 0;
  }
  for(i=0; i<p->nId; i++){
    struct IdList_item *pNewItem = &pNew->a[i];
    struct IdList_item *pOldItem = &p->a[i];
    pNewItem->zName = sqliteStrDup(pOldItem->zName);
    pNewItem->idx = pOldItem->idx;
  }
  return pNew;
}
Select *sqlite3SelectDup(Select *p){
  Select *pNew;
  if( p==0 ) return 0;
  pNew = sqliteMallocRaw( sizeof(*p) );
  if( pNew==0 ) return 0;
  pNew->isDistinct = p->isDistinct;
  pNew->pEList = sqlite3ExprListDup(p->pEList);
  pNew->pSrc = sqlite3SrcListDup(p->pSrc);
  pNew->pWhere = sqlite3ExprDup(p->pWhere);
  pNew->pGroupBy = sqlite3ExprListDup(p->pGroupBy);
  pNew->pHaving = sqlite3ExprDup(p->pHaving);
  pNew->pOrderBy = sqlite3ExprListDup(p->pOrderBy);
  pNew->op = p->op;
  pNew->pPrior = sqlite3SelectDup(p->pPrior);
  pNew->pLimit = sqlite3ExprDup(p->pLimit);
  pNew->pOffset = sqlite3ExprDup(p->pOffset);
  pNew->iLimit = -1;
  pNew->iOffset = -1;
  pNew->isResolved = p->isResolved;
  pNew->isAgg = p->isAgg;
  pNew->usesVirt = 0;
  pNew->disallowOrderBy = 0;
  pNew->pRightmost = 0;
  pNew->addrOpenVirt[0] = -1;
  pNew->addrOpenVirt[1] = -1;
  pNew->addrOpenVirt[2] = -1;
  return pNew;
}
#else
Select *sqlite3SelectDup(Select *p){
  assert( p==0 );
  return 0;
}
#endif


/*
** Add a new element to the end of an expression list.  If pList is
** initially NULL, then create a new expression list.
*/
ExprList *sqlite3ExprListAppend(ExprList *pList, Expr *pExpr, Token *pName){
  if( pList==0 ){
    pList = sqliteMalloc( sizeof(ExprList) );
    if( pList==0 ){
      goto no_mem;
    }
    assert( pList->nAlloc==0 );
  }
  if( pList->nAlloc<=pList->nExpr ){
    struct ExprList_item *a;
    int n = pList->nAlloc*2 + 4;
    a = sqliteRealloc(pList->a, n*sizeof(pList->a[0]));
    if( a==0 ){
      goto no_mem;
    }
    pList->a = a;
    pList->nAlloc = n;
  }
  assert( pList->a!=0 );
  if( pExpr || pName ){
    struct ExprList_item *pItem = &pList->a[pList->nExpr++];
    memset(pItem, 0, sizeof(*pItem));
    pItem->zName = sqlite3NameFromToken(pName);
    pItem->pExpr = pExpr;
  }
  return pList;

no_mem:
  /* Avoid leaking memory if malloc has failed. */
  sqlite3ExprDelete(pExpr);
  sqlite3ExprListDelete(pList);
  return 0;
}

/*
** Delete an entire expression list.
*/
void sqlite3ExprListDelete(ExprList *pList){
  int i;
  struct ExprList_item *pItem;
  if( pList==0 ) return;
  assert( pList->a!=0 || (pList->nExpr==0 && pList->nAlloc==0) );
  assert( pList->nExpr<=pList->nAlloc );
  for(pItem=pList->a, i=0; i<pList->nExpr; i++, pItem++){
    sqlite3ExprDelete(pItem->pExpr);
    sqliteFree(pItem->zName);
  }
  sqliteFree(pList->a);
  sqliteFree(pList);
}

ValuesList *sqlite3ValuesListAppend(ValuesList *valueList, ExprList* exprList) {
    if (exprList == NULL) { return valueList; }
    if (valueList == NULL) {
        valueList = sqliteMalloc(sizeof(ValuesList));
        if (valueList == NULL) { goto no_mem; }
    }

    if (valueList->nAlloc <= valueList->nValues) {
        int allocNum = valueList->nAlloc * 2 + 4;
        ExprList** a = valueList->a;
        a = sqliteRealloc(valueList->a, allocNum * sizeof(ExprList*));
        if (a == NULL) {
            goto no_mem;
        }
        valueList->a = a;
        valueList->nAlloc = allocNum;
    }

    valueList->a[valueList->nValues++] = exprList;
    return valueList;

no_mem:
    sqlite3ExprListDelete(exprList);
    sqlite3ValuesListDelete(valueList);
    return NULL;
}

void sqlite3ValuesListDelete(ValuesList* valuesList) {
    if (valuesList == NULL) { return; }
    int i = 0;
    for (i = 0; i < valuesList->nValues; i++) {
        sqlite3ExprListDelete(valuesList->a[i]);
    }
    sqliteFree(valuesList->a);
    sqliteFree(valuesList);
}

/*
** Walk an expression tree.  Call xFunc for each node visited.
**
** The return value from xFunc determines whether the tree walk continues.
** 0 means continue walking the tree.  1 means do not walk children
** of the current node but continue with siblings.  2 means abandon
** the tree walk completely.
**
** The return value from this routine is 1 to abandon the tree walk
** and 0 to continue.
**
** NOTICE:  This routine does *not* descend into subqueries.
*/
static int walkExprList(ExprList *, int (*)(void *, Expr*), void *);
static int walkExprTree(Expr *pExpr, int (*xFunc)(void*,Expr*), void *pArg){
  int rc;
  if( pExpr==0 ) return 0;
  rc = (*xFunc)(pArg, pExpr);
  if( rc==0 ){
    if( walkExprTree(pExpr->pLeft, xFunc, pArg) ) return 1;
    if( walkExprTree(pExpr->pRight, xFunc, pArg) ) return 1;
    if( walkExprList(pExpr->pList, xFunc, pArg) ) return 1;
  }
  return rc>1;
}

/*
** Call walkExprTree() for every expression in list p.
*/
static int walkExprList(ExprList *p, int (*xFunc)(void *, Expr*), void *pArg){
  int i;
  struct ExprList_item *pItem;
  if( !p ) return 0;
  for(i=p->nExpr, pItem=p->a; i>0; i--, pItem++){
    if( walkExprTree(pItem->pExpr, xFunc, pArg) ) return 1;
  }
  return 0;
}

/*
** Call walkExprTree() for every expression in Select p, not including
** expressions that are part of sub-selects in any FROM clause or the LIMIT
** or OFFSET expressions..
*/
static int walkSelectExpr(Select *p, int (*xFunc)(void *, Expr*), void *pArg){
  walkExprList(p->pEList, xFunc, pArg);
  walkExprTree(p->pWhere, xFunc, pArg);
  walkExprList(p->pGroupBy, xFunc, pArg);
  walkExprTree(p->pHaving, xFunc, pArg);
  walkExprList(p->pOrderBy, xFunc, pArg);
  return 0;
}


/*
** This routine is designed as an xFunc for walkExprTree().
**
** pArg is really a pointer to an integer.  If we can tell by looking
** at pExpr that the expression that contains pExpr is not a constant
** expression, then set *pArg to 0 and return 2 to abandon the tree walk.
** If pExpr does does not disqualify the expression from being a constant
** then do nothing.
**
** After walking the whole tree, if no nodes are found that disqualify
** the expression as constant, then we assume the whole expression
** is constant.  See sqlite3ExprIsConstant() for additional information.
*/
static int exprNodeIsConstant(void *pArg, Expr *pExpr){
  switch( pExpr->op ){
    /* Consider functions to be constant if all their arguments are constant
    ** and *pArg==2 */
    case TK_FUNCTION:
      if( *((int*)pArg)==2 ) return 0;
      /* Fall through */
    case TK_ID:
    case TK_COLUMN:
    case TK_DOT:
    case TK_AGG_FUNCTION:
    case TK_AGG_COLUMN:
#ifndef SQLITE_OMIT_SUBQUERY
    case TK_SELECT:
    case TK_EXISTS:
#endif
      *((int*)pArg) = 0;
      return 2;
    case TK_IN:
      if( pExpr->pSelect ){
        *((int*)pArg) = 0;
        return 2;
      }
    default:
      return 0;
  }
}

/*
** Walk an expression tree.  Return 1 if the expression is constant
** and 0 if it involves variables or function calls.
**
** For the purposes of this function, a double-quoted string (ex: "abc")
** is considered a variable but a single-quoted string (ex: 'abc') is
** a constant.
*/
int sqlite3ExprIsConstant(Expr *p){
  int isConst = 1;
  walkExprTree(p, exprNodeIsConstant, &isConst);
  return isConst;
}

/*
** Walk an expression tree.  Return 1 if the expression is constant
** or a function call with constant arguments.  Return and 0 if there
** are any variables.
**
** For the purposes of this function, a double-quoted string (ex: "abc")
** is considered a variable but a single-quoted string (ex: 'abc') is
** a constant.
*/
int sqlite3ExprIsConstantOrFunction(Expr *p){
  int isConst = 2;
  walkExprTree(p, exprNodeIsConstant, &isConst);
  return isConst!=0;
}

/*
** If the expression p codes a constant integer that is small enough
** to fit in a 32-bit integer, return 1 and put the value of the integer
** in *pValue.  If the expression is not an integer or if it is too big
** to fit in a signed 32-bit integer, return 0 and leave *pValue unchanged.
*/
int sqlite3ExprIsInteger(Expr *p, int *pValue){
  switch( p->op ){
    case TK_INTEGER: {
      if( sqlite3GetInt32((char*)p->token.z, pValue) ){
        return 1;
      }
      break;
    }
    case TK_UPLUS: {
      return sqlite3ExprIsInteger(p->pLeft, pValue);
    }
    case TK_UMINUS: {
      int v;
      if( sqlite3ExprIsInteger(p->pLeft, &v) ){
        *pValue = -v;
        return 1;
      }
      break;
    }
    default: break;
  }
  return 0;
}

/*
** Return TRUE if the given string is a row-id column name.
*/
int sqlite3IsRowid(const char *z){
  if( sqlite3StrICmp(z, "_ROWID_")==0 ) return 1;
  if( sqlite3StrICmp(z, "ROWID")==0 ) return 1;
  if( sqlite3StrICmp(z, "OID")==0 ) return 1;
  return 0;
}

/*
** Given the name of a column of the form X.Y.Z or Y.Z or just Z, look up
** that name in the set of source tables in pSrcList and make the pExpr
** expression node refer back to that source column.  The following changes
** are made to pExpr:
**
**    pExpr->iDb           Set the index in db->aDb[] of the database holding
**                         the table.
**    pExpr->iTable        Set to the cursor number for the table obtained
**                         from pSrcList.
**    pExpr->iColumn       Set to the column number within the table.
**    pExpr->op            Set to TK_COLUMN.
**    pExpr->pLeft         Any expression this points to is deleted
**    pExpr->pRight        Any expression this points to is deleted.
**
** The pDbToken is the name of the database (the "X").  This value may be
** NULL meaning that name is of the form Y.Z or Z.  Any available database
** can be used.  The pTableToken is the name of the table (the "Y").  This
** value can be NULL if pDbToken is also NULL.  If pTableToken is NULL it
** means that the form of the name is Z and that columns from any table
** can be used.
**
** If the name cannot be resolved unambiguously, leave an error message
** in pParse and return non-zero.  Return zero on success.
*/
/* static int lookupName( */
/*   Parse *pParse,       /1* The parsing context *1/ */
/*   Token *pDbToken,     /1* Name of the database containing table, or NULL *1/ */
/*   Token *pTableToken,  /1* Name of table containing column, or NULL *1/ */
/*   Token *pColumnToken, /1* Name of the column. *1/ */
/*   NameContext *pNC,    /1* The name context used to resolve the name *1/ */
/*   Expr *pExpr          /1* Make this EXPR node point to the selected column *1/ */
/* ){ */
/*   char *zDb = 0;       /1* Name of the database.  The "X" in X.Y.Z *1/ */
/*   char *zTab = 0;      /1* Name of the table.  The "Y" in X.Y.Z or Y.Z *1/ */
/*   char *zCol = 0;      /1* Name of the column.  The "Z" *1/ */
/*   int i, j;            /1* Loop counters *1/ */
/*   int cnt = 0;         /1* Number of matching column names *1/ */
/*   int cntTab = 0;      /1* Number of matching table names *1/ */
/*   sqlite3 *db = pParse->db;  /1* The database *1/ */
/*   struct SrcList_item *pItem;       /1* Use for looping over pSrcList items *1/ */
/*   struct SrcList_item *pMatch = 0;  /1* The matching pSrcList item *1/ */
/*   NameContext *pTopNC = pNC;        /1* First namecontext in the list *1/ */

/*   assert( pColumnToken && pColumnToken->z ); /1* The Z in X.Y.Z cannot be NULL *1/ */
/*   zDb = sqlite3NameFromToken(pDbToken); */
/*   zTab = sqlite3NameFromToken(pTableToken); */
/*   zCol = sqlite3NameFromToken(pColumnToken); */
/*   if( sqlite3MallocFailed() ){ */
/*     goto lookupname_end; */
/*   } */

/*   pExpr->iTable = -1; */
/*   while( pNC && cnt==0 ){ */
/*     ExprList *pEList; */
/*     SrcList *pSrcList = pNC->pSrcList; */

/*     if( pSrcList ){ */
/*       for(i=0, pItem=pSrcList->a; i<pSrcList->nSrc; i++, pItem++){ */
/*         Table *pTab; */
/*         int iDb; */
/*         Column *pCol; */

/*         pTab = pItem->pTab; */
/*         assert( pTab!=0 ); */
/*         iDb = sqlite3SchemaToIndex(db, pTab->pSchema); */
/*         assert( pTab->nCol>0 ); */
/*         if( zTab ){ */
/*           if( pItem->zAlias ){ */
/*             char *zTabName = pItem->zAlias; */
/*             if( sqlite3StrICmp(zTabName, zTab)!=0 ) continue; */
/*           }else{ */
/*             char *zTabName = pTab->zName; */
/*             if( zTabName==0 || sqlite3StrICmp(zTabName, zTab)!=0 ) continue; */
/*             if( zDb!=0 && sqlite3StrICmp(db->aDb[iDb].zName, zDb)!=0 ){ */
/*               continue; */
/*             } */
/*           } */
/*         } */
/*         if( 0==(cntTab++) ){ */
/*           pExpr->iTable = pItem->iCursor; */
/*           pExpr->pSchema = pTab->pSchema; */
/*           pMatch = pItem; */
/*         } */
/*         for(j=0, pCol=pTab->aCol; j<pTab->nCol; j++, pCol++){ */
/*           if( sqlite3StrICmp(pCol->zName, zCol)==0 ){ */
/*             const char *zColl = pTab->aCol[j].zColl; */
/*             IdList *pUsing; */
/*             cnt++; */
/*             pExpr->iTable = pItem->iCursor; */
/*             pMatch = pItem; */
/*             pExpr->pSchema = pTab->pSchema; */
/*             /1* Substitute the rowid (column -1) for the INTEGER PRIMARY KEY *1/ */
/*             pExpr->iColumn = j==pTab->iPKey ? -1 : j; */
/*             pExpr->affinity = pTab->aCol[j].affinity; */
/*             pExpr->pColl = sqlite3FindCollSeq(db, ENC(db), zColl,-1, 0); */
/*             if( pItem->jointype & JT_NATURAL ){ */
/*               /1* If this match occurred in the left table of a natural join, */
/*               ** then skip the right table to avoid a duplicate match *1/ */
/*               pItem++; */
/*               i++; */
/*             } */
/*             if( (pUsing = pItem->pUsing)!=0 ){ */
/*               /1* If this match occurs on a column that is in the USING clause */
/*               ** of a join, skip the search of the right table of the join */
/*               ** to avoid a duplicate match there. *1/ */
/*               int k; */
/*               for(k=0; k<pUsing->nId; k++){ */
/*                 if( sqlite3StrICmp(pUsing->a[k].zName, zCol)==0 ){ */
/*                   pItem++; */
/*                   i++; */
/*                   break; */
/*                 } */
/*               } */
/*             } */
/*             break; */
/*           } */
/*         } */
/*       } */
/*     } */

/* #ifndef SQLITE_OMIT_TRIGGER */
/*     /1* If we have not already resolved the name, then maybe */
/*     ** it is a new.* or old.* trigger argument reference */
/*     *1/ */
/*     if( zDb==0 && zTab!=0 && cnt==0 && pParse->trigStack!=0 ){ */
/*       TriggerStack *pTriggerStack = pParse->trigStack; */
/*       Table *pTab = 0; */
/*       if( pTriggerStack->newIdx != -1 && sqlite3StrICmp("new", zTab) == 0 ){ */
/*         pExpr->iTable = pTriggerStack->newIdx; */
/*         assert( pTriggerStack->pTab ); */
/*         pTab = pTriggerStack->pTab; */
/*       }else if( pTriggerStack->oldIdx != -1 && sqlite3StrICmp("old", zTab)==0 ){ */
/*         pExpr->iTable = pTriggerStack->oldIdx; */
/*         assert( pTriggerStack->pTab ); */
/*         pTab = pTriggerStack->pTab; */
/*       } */

/*       if( pTab ){ */
/*         int iCol; */
/*         Column *pCol = pTab->aCol; */

/*         pExpr->pSchema = pTab->pSchema; */
/*         cntTab++; */
/*         for(iCol=0; iCol < pTab->nCol; iCol++, pCol++) { */
/*           if( sqlite3StrICmp(pCol->zName, zCol)==0 ){ */
/*             const char *zColl = pTab->aCol[iCol].zColl; */
/*             cnt++; */
/*             pExpr->iColumn = iCol==pTab->iPKey ? -1 : iCol; */
/*             pExpr->affinity = pTab->aCol[iCol].affinity; */
/*             pExpr->pColl = sqlite3FindCollSeq(db, ENC(db), zColl,-1, 0); */
/*             pExpr->pTab = pTab; */
/*             break; */
/*           } */
/*         } */
/*       } */
/*     } */
/* #endif /1* !defined(SQLITE_OMIT_TRIGGER) *1/ */

/*     /* */
/*     ** Perhaps the name is a reference to the ROWID */
/*     *1/ */
/*     if( cnt==0 && cntTab==1 && sqlite3IsRowid(zCol) ){ */
/*       cnt = 1; */
/*       pExpr->iColumn = -1; */
/*       pExpr->affinity = SQLITE_AFF_INTEGER; */
/*     } */

/*     /* */
/*     ** If the input is of the form Z (not Y.Z or X.Y.Z) then the name Z */
/*     ** might refer to an result-set alias.  This happens, for example, when */
/*     ** we are resolving names in the WHERE clause of the following command: */
/*     ** */
/*     **     SELECT a+b AS x FROM table WHERE x<10; */
/*     ** */
/*     ** In cases like this, replace pExpr with a copy of the expression that */
/*     ** forms the result set entry ("a+b" in the example) and return immediately. */
/*     ** Note that the expression in the result set should have already been */
/*     ** resolved by the time the WHERE clause is resolved. */
/*     *1/ */
/*     if( cnt==0 && (pEList = pNC->pEList)!=0 && zTab==0 ){ */
/*       for(j=0; j<pEList->nExpr; j++){ */
/*         char *zAs = pEList->a[j].zName; */
/*         if( zAs!=0 && sqlite3StrICmp(zAs, zCol)==0 ){ */
/*           assert( pExpr->pLeft==0 && pExpr->pRight==0 ); */
/*           pExpr->op = TK_AS; */
/*           pExpr->iColumn = j; */
/*           pExpr->pLeft = sqlite3ExprDup(pEList->a[j].pExpr); */
/*           cnt = 1; */
/*           assert( zTab==0 && zDb==0 ); */
/*           goto lookupname_end_2; */
/*         } */
/*       } */
/*     } */

/*     /1* Advance to the next name context.  The loop will exit when either */
/*     ** we have a match (cnt>0) or when we run out of name contexts. */
/*     *1/ */
/*     if( cnt==0 ){ */
/*       pNC = pNC->pNext; */
/*     } */
/*   } */

/*   /* */
/*   ** If X and Y are NULL (in other words if only the column name Z is */
/*   ** supplied) and the value of Z is enclosed in double-quotes, then */
/*   ** Z is a string literal if it doesn't match any column names.  In that */
/*   ** case, we need to return right away and not make any changes to */
/*   ** pExpr. */
/*   ** */
/*   ** Because no reference was made to outer contexts, the pNC->nRef */
/*   ** fields are not changed in any context. */
/*   *1/ */
/*   if( cnt==0 && zTab==0 && pColumnToken->z[0]=='"' ){ */
/*     sqliteFree(zCol); */
/*     return 0; */
/*   } */

/*   /* */
/*   ** cnt==0 means there was not match.  cnt>1 means there were two or */
/*   ** more matches.  Either way, we have an error. */
/*   *1/ */
/*   if( cnt!=1 ){ */
/*     char *z = 0; */
/*     char *zErr; */
/*     zErr = cnt==0 ? "no such column: %s" : "ambiguous column name: %s"; */
/*     if( zDb ){ */
/*       sqlite3SetString(&z, zDb, ".", zTab, ".", zCol, (char*)0); */
/*     }else if( zTab ){ */
/*       sqlite3SetString(&z, zTab, ".", zCol, (char*)0); */
/*     }else{ */
/*       z = sqliteStrDup(zCol); */
/*     } */
/*     sqlite3ErrorMsg(pParse, zErr, z); */
/*     sqliteFree(z); */
/*     pTopNC->nErr++; */
/*   } */

/*   /1* If a column from a table in pSrcList is referenced, then record */
/*   ** this fact in the pSrcList.a[].colUsed bitmask.  Column 0 causes */
/*   ** bit 0 to be set.  Column 1 sets bit 1.  And so forth.  If the */
/*   ** column number is greater than the number of bits in the bitmask */
/*   ** then set the high-order bit of the bitmask. */
/*   *1/ */
/*   if( pExpr->iColumn>=0 && pMatch!=0 ){ */
/*     int n = pExpr->iColumn; */
/*     if( n>=sizeof(Bitmask)*8 ){ */
/*       n = sizeof(Bitmask)*8-1; */
/*     } */
/*     assert( pMatch->iCursor==pExpr->iTable ); */
/*     pMatch->colUsed |= 1<<n; */
/*   } */

/* lookupname_end: */
/*   /1* Clean up and return */
/*   *1/ */
/*   sqliteFree(zDb); */
/*   sqliteFree(zTab); */
/*   sqlite3ExprDelete(pExpr->pLeft); */
/*   pExpr->pLeft = 0; */
/*   sqlite3ExprDelete(pExpr->pRight); */
/*   pExpr->pRight = 0; */
/*   pExpr->op = TK_COLUMN; */
/* lookupname_end_2: */
/*   sqliteFree(zCol); */
/*   if( cnt==1 ){ */
/*     assert( pNC!=0 ); */
/*     sqlite3AuthRead(pParse, pExpr, pNC->pSrcList); */
/*     if( pMatch && !pMatch->pSelect ){ */
/*       pExpr->pTab = pMatch->pTab; */
/*     } */
/*     /1* Increment the nRef value on all name contexts from TopNC up to */
/*     ** the point where the name matched. *1/ */
/*     for(;;){ */
/*       assert( pTopNC!=0 ); */
/*       pTopNC->nRef++; */
/*       if( pTopNC==pNC ) break; */
/*       pTopNC = pTopNC->pNext; */
/*     } */
/*     return 0; */
/*   } else { */
/*     return 1; */
/*   } */
/* } */

/*
** This routine is designed as an xFunc for walkExprTree().
**
** Resolve symbolic names into TK_COLUMN operators for the current
** node in the expression tree.  Return 0 to continue the search down
** the tree or 2 to abort the tree walk.
**
** This routine also does error checking and name resolution for
** function names.  The operator for aggregate functions is changed
** to TK_AGG_FUNCTION.
*/
/* static int nameResolverStep(void *pArg, Expr *pExpr){ */
/*   NameContext *pNC = (NameContext*)pArg; */
/*   Parse *pParse; */

/*   if( pExpr==0 ) return 1; */
/*   assert( pNC!=0 ); */
/*   pParse = pNC->pParse; */

/*   if( ExprHasAnyProperty(pExpr, EP_Resolved) ) return 1; */
/*   ExprSetProperty(pExpr, EP_Resolved); */
/* #ifndef NDEBUG */
/*   if( pNC->pSrcList && pNC->pSrcList->nAlloc>0 ){ */
/*     SrcList *pSrcList = pNC->pSrcList; */
/*     int i; */
/*     for(i=0; i<pNC->pSrcList->nSrc; i++){ */
/*       assert( pSrcList->a[i].iCursor>=0 && pSrcList->a[i].iCursor<pParse->nTab); */
/*     } */
/*   } */
/* #endif */
/*   switch( pExpr->op ){ */
/*     /1* Double-quoted strings (ex: "abc") are used as identifiers if */
/*     ** possible.  Otherwise they remain as strings.  Single-quoted */
/*     ** strings (ex: 'abc') are always string literals. */
/*     *1/ */
/*     case TK_STRING: { */
/*       if( pExpr->token.z[0]=='\'' ) break; */
/*       /1* Fall thru into the TK_ID case if this is a double-quoted string *1/ */
/*     } */
/*     /1* A lone identifier is the name of a column. */
/*     *1/ */
/*     case TK_ID: { */
/*       lookupName(pParse, 0, 0, &pExpr->token, pNC, pExpr); */
/*       return 1; */
/*     } */

/*     /1* A table name and column name:     ID.ID */
/*     ** Or a database, table and column:  ID.ID.ID */
/*     *1/ */
/*     case TK_DOT: { */
/*       Token *pColumn; */
/*       Token *pTable; */
/*       Token *pDb; */
/*       Expr *pRight; */

/*       /1* if( pSrcList==0 ) break; *1/ */
/*       pRight = pExpr->pRight; */
/*       if( pRight->op==TK_ID ){ */
/*         pDb = 0; */
/*         pTable = &pExpr->pLeft->token; */
/*         pColumn = &pRight->token; */
/*       }else{ */
/*         assert( pRight->op==TK_DOT ); */
/*         pDb = &pExpr->pLeft->token; */
/*         pTable = &pRight->pLeft->token; */
/*         pColumn = &pRight->pRight->token; */
/*       } */
/*       lookupName(pParse, pDb, pTable, pColumn, pNC, pExpr); */
/*       return 1; */
/*     } */

/*     /1* Resolve function names */
/*     *1/ */
/*     case TK_CONST_FUNC: */
/*     case TK_FUNCTION: { */
/*       ExprList *pList = pExpr->pList;    /1* The argument list *1/ */
/*       int n = pList ? pList->nExpr : 0;  /1* Number of arguments *1/ */
/*       int no_such_func = 0;       /1* True if no such function exists *1/ */
/*       int wrong_num_args = 0;     /1* True if wrong number of arguments *1/ */
/*       int is_agg = 0;             /1* True if is an aggregate function *1/ */
/*       int i; */
/*       int nId;                    /1* Number of characters in function name *1/ */
/*       const char *zId;            /1* The function name. *1/ */
/*       FuncDef *pDef;              /1* Information about the function *1/ */
/*       int enc = ENC(pParse->db);  /1* The database encoding *1/ */

/*       zId = (char*)pExpr->token.z; */
/*       nId = pExpr->token.n; */
/*       pDef = sqlite3FindFunction(pParse->db, zId, nId, n, enc, 0); */
/*       if( pDef==0 ){ */
/*         pDef = sqlite3FindFunction(pParse->db, zId, nId, -1, enc, 0); */
/*         if( pDef==0 ){ */
/*           no_such_func = 1; */
/*         }else{ */
/*           wrong_num_args = 1; */
/*         } */
/*       }else{ */
/*         is_agg = pDef->xFunc==0; */
/*       } */
/*       if( is_agg && !pNC->allowAgg ){ */
/*         sqlite3ErrorMsg(pParse, "misuse of aggregate function %.*s()", nId,zId); */
/*         pNC->nErr++; */
/*         is_agg = 0; */
/*       }else if( no_such_func ){ */
/*         sqlite3ErrorMsg(pParse, "no such function: %.*s", nId, zId); */
/*         pNC->nErr++; */
/*       }else if( wrong_num_args ){ */
/*         sqlite3ErrorMsg(pParse,"wrong number of arguments to function %.*s()", */
/*              nId, zId); */
/*         pNC->nErr++; */
/*       } */
/*       if( is_agg ){ */
/*         pExpr->op = TK_AGG_FUNCTION; */
/*         pNC->hasAgg = 1; */
/*       } */
/*       if( is_agg ) pNC->allowAgg = 0; */
/*       for(i=0; pNC->nErr==0 && i<n; i++){ */
/*         walkExprTree(pList->a[i].pExpr, nameResolverStep, pNC); */
/*       } */
/*       if( is_agg ) pNC->allowAgg = 1; */
/*       /1* FIX ME:  Compute pExpr->affinity based on the expected return */
/*       ** type of the function */
/*       *1/ */
/*       return is_agg; */
/*     } */
/* #ifndef SQLITE_OMIT_SUBQUERY */
/*     case TK_SELECT: */
/*     case TK_EXISTS: */
/* #endif */
/*     case TK_IN: { */
/*       if( pExpr->pSelect ){ */
/*         int nRef = pNC->nRef; */
/* #ifndef SQLITE_OMIT_CHECK */
/*         if( pNC->isCheck ){ */
/*           sqlite3ErrorMsg(pParse,"subqueries prohibited in CHECK constraints"); */
/*         } */
/* #endif */
/*         sqlite3SelectResolve(pParse, pExpr->pSelect, pNC); */
/*         assert( pNC->nRef>=nRef ); */
/*         if( nRef!=pNC->nRef ){ */
/*           ExprSetProperty(pExpr, EP_VarSelect); */
/*         } */
/*       } */
/*       break; */
/*     } */
/* #ifndef SQLITE_OMIT_CHECK */
/*     case TK_VARIABLE: { */
/*       if( pNC->isCheck ){ */
/*         sqlite3ErrorMsg(pParse,"parameters prohibited in CHECK constraints"); */
/*       } */
/*       break; */
/*     } */
/* #endif */
/*   } */
/*   return 0; */
/* } */

/*
** This routine walks an expression tree and resolves references to
** table columns.  Nodes of the form ID.ID or ID resolve into an
** index to the table in the table list and a column offset.  The
** Expr.opcode for such nodes is changed to TK_COLUMN.  The Expr.iTable
** value is changed to the index of the referenced table in pTabList
** plus the "base" value.  The base value will ultimately become the
** VDBE cursor number for a cursor that is pointing into the referenced
** table.  The Expr.iColumn value is changed to the index of the column
** of the referenced table.  The Expr.iColumn value for the special
** ROWID column is -1.  Any INTEGER PRIMARY KEY column is tried as an
** alias for ROWID.
**
** Also resolve function names and check the functions for proper
** usage.  Make sure all function names are recognized and all functions
** have the correct number of arguments.  Leave an error message
** in pParse->zErrMsg if anything is amiss.  Return the number of errors.
**
** If the expression contains aggregate functions then set the EP_Agg
** property on the expression.
*/
/* int sqlite3ExprResolveNames( */
/*   NameContext *pNC,       /1* Namespace to resolve expressions in. *1/ */
/*   Expr *pExpr             /1* The expression to be analyzed. *1/ */
/* ){ */
/*   int savedHasAgg; */
/*   if( pExpr==0 ) return 0; */
/*   savedHasAgg = pNC->hasAgg; */
/*   pNC->hasAgg = 0; */
/*   walkExprTree(pExpr, nameResolverStep, pNC); */
/*   if( pNC->nErr>0 ){ */
/*     ExprSetProperty(pExpr, EP_Error); */
/*   } */
/*   if( pNC->hasAgg ){ */
/*     ExprSetProperty(pExpr, EP_Agg); */
/*   }else if( savedHasAgg ){ */
/*     pNC->hasAgg = 1; */
/*   } */
/*   return ExprHasProperty(pExpr, EP_Error); */
/* } */

/*
** A pointer instance of this structure is used to pass information
** through walkExprTree into codeSubqueryStep().
*/
typedef struct QueryCoder QueryCoder;
struct QueryCoder {
  Parse *pParse;       /* The parsing context */
  NameContext *pNC;    /* Namespace of first enclosing query */
};


/*
** Generate code for scalar subqueries used as an expression
** and IN operators.  Examples:
**
**     (SELECT a FROM b)          -- subquery
**     EXISTS (SELECT a FROM b)   -- EXISTS subquery
**     x IN (4,5,11)              -- IN operator with list on right-hand side
**     x IN (SELECT a FROM b)     -- IN operator with subquery on the right
**
** The pExpr parameter describes the expression that contains the IN
** operator or subquery.
*/
/* #ifndef SQLITE_OMIT_SUBQUERY */
/* void sqlite3CodeSubselect(Parse *pParse, Expr *pExpr){ */
/*   int testAddr = 0;                       /1* One-time test address *1/ */
/*   Vdbe *v = sqlite3GetVdbe(pParse); */
/*   if( v==0 ) return; */

/*   /1* This code must be run in its entirety every time it is encountered */
/*   ** if any of the following is true: */
/*   ** */
/*   **    *  The right-hand side is a correlated subquery */
/*   **    *  The right-hand side is an expression list containing variables */
/*   **    *  We are inside a trigger */
/*   ** */
/*   ** If all of the above are false, then we can run this code just once */
/*   ** save the results, and reuse the same result on subsequent invocations. */
/*   *1/ */
/*   if( !ExprHasAnyProperty(pExpr, EP_VarSelect) && !pParse->trigStack ){ */
/*     int mem = pParse->nMem++; */
/*     sqlite3VdbeAddOp(v, OP_MemLoad, mem, 0); */
/*     testAddr = sqlite3VdbeAddOp(v, OP_If, 0, 0); */
/*     assert( testAddr>0 || sqlite3MallocFailed() ); */
/*     sqlite3VdbeAddOp(v, OP_MemInt, 1, mem); */
/*   } */

/*   switch( pExpr->op ){ */
/*     case TK_IN: { */
/*       char affinity; */
/*       KeyInfo keyInfo; */
/*       int addr;        /1* Address of OP_OpenVirtual instruction *1/ */

/*       affinity = sqlite3ExprAffinity(pExpr->pLeft); */

/*       /1* Whether this is an 'x IN(SELECT...)' or an 'x IN(<exprlist>)' */
/*       ** expression it is handled the same way. A virtual table is */
/*       ** filled with single-field index keys representing the results */
/*       ** from the SELECT or the <exprlist>. */
/*       ** */
/*       ** If the 'x' expression is a column value, or the SELECT... */
/*       ** statement returns a column value, then the affinity of that */
/*       ** column is used to build the index keys. If both 'x' and the */
/*       ** SELECT... statement are columns, then numeric affinity is used */
/*       ** if either column has NUMERIC or INTEGER affinity. If neither */
/*       ** 'x' nor the SELECT... statement are columns, then numeric affinity */
/*       ** is used. */
/*       *1/ */
/*       pExpr->iTable = pParse->nTab++; */
/*       addr = sqlite3VdbeAddOp(v, OP_OpenVirtual, pExpr->iTable, 0); */
/*       memset(&keyInfo, 0, sizeof(keyInfo)); */
/*       keyInfo.nField = 1; */
/*       sqlite3VdbeAddOp(v, OP_SetNumColumns, pExpr->iTable, 1); */

/*       if( pExpr->pSelect ){ */
/*         /1* Case 1:     expr IN (SELECT ...) */
/*         ** */
/*         ** Generate code to write the results of the select into the temporary */
/*         ** table allocated and opened above. */
/*         *1/ */
/*         int iParm = pExpr->iTable +  (((int)affinity)<<16); */
/*         ExprList *pEList; */
/*         assert( (pExpr->iTable&0x0000FFFF)==pExpr->iTable ); */
/*         sqlite3Select(pParse, pExpr->pSelect, SRT_Set, iParm, 0, 0, 0, 0); */
/*         pEList = pExpr->pSelect->pEList; */
/*         if( pEList && pEList->nExpr>0 ){ */
/*           keyInfo.aColl[0] = binaryCompareCollSeq(pParse, pExpr->pLeft, */
/*               pEList->a[0].pExpr); */
/*         } */
/*       }else if( pExpr->pList ){ */
/*         /1* Case 2:     expr IN (exprlist) */
/*         ** */
/* 	** For each expression, build an index key from the evaluation and */
/*         ** store it in the temporary table. If <expr> is a column, then use */
/*         ** that columns affinity when building index keys. If <expr> is not */
/*         ** a column, use numeric affinity. */
/*         *1/ */
/*         int i; */
/*         ExprList *pList = pExpr->pList; */
/*         struct ExprList_item *pItem; */

/*         if( !affinity ){ */
/*           affinity = SQLITE_AFF_NUMERIC; */
/*         } */
/*         keyInfo.aColl[0] = pExpr->pLeft->pColl; */

/*         /1* Loop through each expression in <exprlist>. *1/ */
/*         for(i=pList->nExpr, pItem=pList->a; i>0; i--, pItem++){ */
/*           Expr *pE2 = pItem->pExpr; */

/*           /1* If the expression is not constant then we will need to */
/*           ** disable the test that was generated above that makes sure */
/*           ** this code only executes once.  Because for a non-constant */
/*           ** expression we need to rerun this code each time. */
/*           *1/ */
/*           if( testAddr>0 && !sqlite3ExprIsConstant(pE2) ){ */
/*             sqlite3VdbeChangeToNoop(v, testAddr-1, 3); */
/*             testAddr = 0; */
/*           } */

/*           /1* Evaluate the expression and insert it into the temp table *1/ */
/*           sqlite3ExprCode(pParse, pE2); */
/*           sqlite3VdbeOp3(v, OP_MakeRecord, 1, 0, &affinity, 1); */
/*           sqlite3VdbeAddOp(v, OP_IdxInsert, pExpr->iTable, 0); */
/*         } */
/*       } */
/*       sqlite3VdbeChangeP3(v, addr, (void *)&keyInfo, P3_KEYINFO); */
/*       break; */
/*     } */

/*     case TK_EXISTS: */
/*     case TK_SELECT: { */
/*       /1* This has to be a scalar SELECT.  Generate code to put the */
/*       ** value of this select in a memory cell and record the number */
/*       ** of the memory cell in iColumn. */
/*       *1/ */
/*       static const Token one = { (u8*)"1", 0, 1 }; */
/*       Select *pSel; */
/*       int iMem; */
/*       int sop; */

/*       pExpr->iColumn = iMem = pParse->nMem++; */
/*       pSel = pExpr->pSelect; */
/*       if( pExpr->op==TK_SELECT ){ */
/*         sop = SRT_Mem; */
/*         sqlite3VdbeAddOp(v, OP_MemNull, iMem, 0); */
/*         VdbeComment((v, "# Init subquery result")); */
/*       }else{ */
/*         sop = SRT_Exists; */
/*         sqlite3VdbeAddOp(v, OP_MemInt, 0, iMem); */
/*         VdbeComment((v, "# Init EXISTS result")); */
/*       } */
/*       sqlite3ExprDelete(pSel->pLimit); */
/*       pSel->pLimit = sqlite3Expr(TK_INTEGER, 0, 0, &one); */
/*       sqlite3Select(pParse, pSel, sop, iMem, 0, 0, 0, 0); */
/*       break; */
/*     } */
/*   } */

/*   if( testAddr ){ */
/*     sqlite3VdbeJumpHere(v, testAddr); */
/*   } */
/*   return; */
/* } */
/* #endif /1* SQLITE_OMIT_SUBQUERY *1/ */

/*
** Generate an instruction that will put the integer describe by
** text z[0..n-1] on the stack.
*/
/* static void codeInteger(Vdbe *v, const char *z, int n){ */
/*   int i; */
/*   if( sqlite3GetInt32(z, &i) ){ */
/*     sqlite3VdbeAddOp(v, OP_Integer, i, 0); */
/*   }else if( sqlite3FitsIn64Bits(z) ){ */
/*     sqlite3VdbeOp3(v, OP_Int64, 0, 0, z, n); */
/*   }else{ */
/*     sqlite3VdbeOp3(v, OP_Real, 0, 0, z, n); */
/*   } */
/* } */

/*
** Generate code into the current Vdbe to evaluate the given
** expression and leave the result on the top of stack.
**
** This code depends on the fact that certain token values (ex: TK_EQ)
** are the same as opcode values (ex: OP_Eq) that implement the corresponding
** operation.  Special comments in vdbe.c and the mkopcodeh.awk script in
** the make process cause these values to align.  Assert()s in the code
** below verify that the numbers are aligned correctly.
*/
/* void sqlite3ExprCode(Parse *pParse, Expr *pExpr){ */
/*   Vdbe *v = pParse->pVdbe; */
/*   int op; */
/*   int stackChng = 1;    /1* Amount of change to stack depth *1/ */

/*   if( v==0 ) return; */
/*   if( pExpr==0 ){ */
/*     sqlite3VdbeAddOp(v, OP_Null, 0, 0); */
/*     return; */
/*   } */
/*   op = pExpr->op; */
/*   switch( op ){ */
/*     case TK_AGG_COLUMN: { */
/*       AggInfo *pAggInfo = pExpr->pAggInfo; */
/*       struct AggInfo_col *pCol = &pAggInfo->aCol[pExpr->iAgg]; */
/*       if( !pAggInfo->directMode ){ */
/*         sqlite3VdbeAddOp(v, OP_MemLoad, pCol->iMem, 0); */
/*         break; */
/*       }else if( pAggInfo->useSortingIdx ){ */
/*         sqlite3VdbeAddOp(v, OP_Column, pAggInfo->sortingIdx, */
/*                               pCol->iSorterColumn); */
/*         break; */
/*       } */
/*       /1* Otherwise, fall thru into the TK_COLUMN case *1/ */
/*     } */
/*     case TK_COLUMN: { */
/*       if( pExpr->iTable<0 ){ */
/*         /1* This only happens when coding check constraints *1/ */
/*         assert( pParse->ckOffset>0 ); */
/*         sqlite3VdbeAddOp(v, OP_Dup, pParse->ckOffset-pExpr->iColumn-1, 1); */
/*       }else if( pExpr->iColumn>=0 ){ */
/*         Table *pTab = pExpr->pTab; */
/*         int iCol = pExpr->iColumn; */
/*         sqlite3VdbeAddOp(v, OP_Column, pExpr->iTable, iCol); */
/*         sqlite3ColumnDefault(v, pTab, iCol); */
/* #ifndef SQLITE_OMIT_FLOATING_POINT */
/*         if( pTab && pTab->aCol[iCol].affinity==SQLITE_AFF_REAL ){ */
/*           sqlite3VdbeAddOp(v, OP_RealAffinity, 0, 0); */
/*         } */
/* #endif */
/*       }else{ */
/*         sqlite3VdbeAddOp(v, OP_Rowid, pExpr->iTable, 0); */
/*       } */
/*       break; */
/*     } */
/*     case TK_INTEGER: { */
/*       codeInteger(v, (char*)pExpr->token.z, pExpr->token.n); */
/*       break; */
/*     } */
/*     case TK_FLOAT: */
/*     case TK_STRING: { */
/*       assert( TK_FLOAT==OP_Real ); */
/*       assert( TK_STRING==OP_String8 ); */
/*       sqlite3DequoteExpr(pExpr); */
/*       sqlite3VdbeOp3(v, op, 0, 0, (char*)pExpr->token.z, pExpr->token.n); */
/*       break; */
/*     } */
/*     case TK_NULL: { */
/*       sqlite3VdbeAddOp(v, OP_Null, 0, 0); */
/*       break; */
/*     } */
/* #ifndef SQLITE_OMIT_BLOB_LITERAL */
/*     case TK_BLOB: { */
/*       int n; */
/*       const char *z; */
/*       assert( TK_BLOB==OP_HexBlob ); */
/*       n = pExpr->token.n - 3; */
/*       z = (char*)pExpr->token.z + 2; */
/*       assert( n>=0 ); */
/*       if( n==0 ){ */
/*         z = ""; */
/*       } */
/*       sqlite3VdbeOp3(v, op, 0, 0, z, n); */
/*       break; */
/*     } */
/* #endif */
/*     case TK_VARIABLE: { */
/*       sqlite3VdbeAddOp(v, OP_Variable, pExpr->iTable, 0); */
/*       if( pExpr->token.n>1 ){ */
/*         sqlite3VdbeChangeP3(v, -1, (char*)pExpr->token.z, pExpr->token.n); */
/*       } */
/*       break; */
/*     } */
/*     case TK_REGISTER: { */
/*       sqlite3VdbeAddOp(v, OP_MemLoad, pExpr->iTable, 0); */
/*       break; */
/*     } */
/* #ifndef SQLITE_OMIT_CAST */
/*     case TK_CAST: { */
/*       /1* Expressions of the form:   CAST(pLeft AS token) *1/ */
/*       int aff, to_op; */
/*       sqlite3ExprCode(pParse, pExpr->pLeft); */
/*       aff = sqlite3AffinityType(&pExpr->token); */
/*       to_op = aff - SQLITE_AFF_TEXT + OP_ToText; */
/*       assert( to_op==OP_ToText    || aff!=SQLITE_AFF_TEXT    ); */
/*       assert( to_op==OP_ToBlob    || aff!=SQLITE_AFF_NONE    ); */
/*       assert( to_op==OP_ToNumeric || aff!=SQLITE_AFF_NUMERIC ); */
/*       assert( to_op==OP_ToInt     || aff!=SQLITE_AFF_INTEGER ); */
/*       assert( to_op==OP_ToReal    || aff!=SQLITE_AFF_REAL    ); */
/*       sqlite3VdbeAddOp(v, to_op, 0, 0); */
/*       stackChng = 0; */
/*       break; */
/*     } */
/* #endif /1* SQLITE_OMIT_CAST *1/ */
/*     case TK_LT: */
/*     case TK_LE: */
/*     case TK_GT: */
/*     case TK_GE: */
/*     case TK_NE: */
/*     case TK_EQ: { */
/*       assert( TK_LT==OP_Lt ); */
/*       assert( TK_LE==OP_Le ); */
/*       assert( TK_GT==OP_Gt ); */
/*       assert( TK_GE==OP_Ge ); */
/*       assert( TK_EQ==OP_Eq ); */
/*       assert( TK_NE==OP_Ne ); */
/*       sqlite3ExprCode(pParse, pExpr->pLeft); */
/*       sqlite3ExprCode(pParse, pExpr->pRight); */
/*       codeCompare(pParse, pExpr->pLeft, pExpr->pRight, op, 0, 0); */
/*       stackChng = -1; */
/*       break; */
/*     } */
/*     case TK_AND: */
/*     case TK_OR: */
/*     case TK_PLUS: */
/*     case TK_STAR: */
/*     case TK_MINUS: */
/*     case TK_REM: */
/*     case TK_BITAND: */
/*     case TK_BITOR: */
/*     case TK_SLASH: */
/*     case TK_LSHIFT: */
/*     case TK_RSHIFT: */
/*     case TK_CONCAT: { */
/*       assert( TK_AND==OP_And ); */
/*       assert( TK_OR==OP_Or ); */
/*       assert( TK_PLUS==OP_Add ); */
/*       assert( TK_MINUS==OP_Subtract ); */
/*       assert( TK_REM==OP_Remainder ); */
/*       assert( TK_BITAND==OP_BitAnd ); */
/*       assert( TK_BITOR==OP_BitOr ); */
/*       assert( TK_SLASH==OP_Divide ); */
/*       assert( TK_LSHIFT==OP_ShiftLeft ); */
/*       assert( TK_RSHIFT==OP_ShiftRight ); */
/*       assert( TK_CONCAT==OP_Concat ); */
/*       sqlite3ExprCode(pParse, pExpr->pLeft); */
/*       sqlite3ExprCode(pParse, pExpr->pRight); */
/*       sqlite3VdbeAddOp(v, op, 0, 0); */
/*       stackChng = -1; */
/*       break; */
/*     } */
/*     case TK_UMINUS: { */
/*       Expr *pLeft = pExpr->pLeft; */
/*       assert( pLeft ); */
/*       if( pLeft->op==TK_FLOAT || pLeft->op==TK_INTEGER ){ */
/*         Token *p = &pLeft->token; */
/*         char *z = sqlite3MPrintf("-%.*s", p->n, p->z); */
/*         if( pLeft->op==TK_FLOAT ){ */
/*           sqlite3VdbeOp3(v, OP_Real, 0, 0, z, p->n+1); */
/*         }else{ */
/*           codeInteger(v, z, p->n+1); */
/*         } */
/*         sqliteFree(z); */
/*         break; */
/*       } */
/*       /1* Fall through into TK_NOT *1/ */
/*     } */
/*     case TK_BITNOT: */
/*     case TK_NOT: { */
/*       assert( TK_BITNOT==OP_BitNot ); */
/*       assert( TK_NOT==OP_Not ); */
/*       sqlite3ExprCode(pParse, pExpr->pLeft); */
/*       sqlite3VdbeAddOp(v, op, 0, 0); */
/*       stackChng = 0; */
/*       break; */
/*     } */
/*     case TK_ISNULL: */
/*     case TK_NOTNULL: { */
/*       int dest; */
/*       assert( TK_ISNULL==OP_IsNull ); */
/*       assert( TK_NOTNULL==OP_NotNull ); */
/*       sqlite3VdbeAddOp(v, OP_Integer, 1, 0); */
/*       sqlite3ExprCode(pParse, pExpr->pLeft); */
/*       dest = sqlite3VdbeCurrentAddr(v) + 2; */
/*       sqlite3VdbeAddOp(v, op, 1, dest); */
/*       sqlite3VdbeAddOp(v, OP_AddImm, -1, 0); */
/*       stackChng = 0; */
/*       break; */
/*     } */
/*     case TK_AGG_FUNCTION: { */
/*       AggInfo *pInfo = pExpr->pAggInfo; */
/*       if( pInfo==0 ){ */
/*         sqlite3ErrorMsg(pParse, "misuse of aggregate: %T", */
/*             &pExpr->span); */
/*       }else{ */
/*         sqlite3VdbeAddOp(v, OP_MemLoad, pInfo->aFunc[pExpr->iAgg].iMem, 0); */
/*       } */
/*       break; */
/*     } */
/*     case TK_CONST_FUNC: */
/*     case TK_FUNCTION: { */
/*       ExprList *pList = pExpr->pList; */
/*       int nExpr = pList ? pList->nExpr : 0; */
/*       FuncDef *pDef; */
/*       int nId; */
/*       const char *zId; */
/*       int constMask = 0; */
/*       int i; */
/*       u8 enc = ENC(pParse->db); */
/*       CollSeq *pColl = 0; */
/*       zId = (char*)pExpr->token.z; */
/*       nId = pExpr->token.n; */
/*       pDef = sqlite3FindFunction(pParse->db, zId, nId, nExpr, enc, 0); */
/*       assert( pDef!=0 ); */
/*       nExpr = sqlite3ExprCodeExprList(pParse, pList); */
/*       for(i=0; i<nExpr && i<32; i++){ */
/*         if( sqlite3ExprIsConstant(pList->a[i].pExpr) ){ */
/*           constMask |= (1<<i); */
/*         } */
/*         if( pDef->needCollSeq && !pColl ){ */
/*           pColl = sqlite3ExprCollSeq(pParse, pList->a[i].pExpr); */
/*         } */
/*       } */
/*       if( pDef->needCollSeq ){ */
/*         if( !pColl ) pColl = pParse->db->pDfltColl; */
/*         sqlite3VdbeOp3(v, OP_CollSeq, 0, 0, (char *)pColl, P3_COLLSEQ); */
/*       } */
/*       sqlite3VdbeOp3(v, OP_Function, constMask, nExpr, (char*)pDef, P3_FUNCDEF); */
/*       stackChng = 1-nExpr; */
/*       break; */
/*     } */
/* #ifndef SQLITE_OMIT_SUBQUERY */
/*     case TK_EXISTS: */
/*     case TK_SELECT: { */
/*       if( pExpr->iColumn==0 ){ */
/*         sqlite3CodeSubselect(pParse, pExpr); */
/*       } */
/*       sqlite3VdbeAddOp(v, OP_MemLoad, pExpr->iColumn, 0); */
/*       VdbeComment((v, "# load subquery result")); */
/*       break; */
/*     } */
/*     case TK_IN: { */
/*       int addr; */
/*       char affinity; */
/*       int ckOffset = pParse->ckOffset; */
/*       sqlite3CodeSubselect(pParse, pExpr); */

/*       /1* Figure out the affinity to use to create a key from the results */
/*       ** of the expression. affinityStr stores a static string suitable for */
/*       ** P3 of OP_MakeRecord. */
/*       *1/ */
/*       affinity = comparisonAffinity(pExpr); */

/*       sqlite3VdbeAddOp(v, OP_Integer, 1, 0); */
/*       pParse->ckOffset = ckOffset+1; */

/*       /1* Code the <expr> from "<expr> IN (...)". The temporary table */
/*       ** pExpr->iTable contains the values that make up the (...) set. */
/*       *1/ */
/*       sqlite3ExprCode(pParse, pExpr->pLeft); */
/*       addr = sqlite3VdbeCurrentAddr(v); */
/*       sqlite3VdbeAddOp(v, OP_NotNull, -1, addr+4);            /1* addr + 0 *1/ */
/*       sqlite3VdbeAddOp(v, OP_Pop, 2, 0); */
/*       sqlite3VdbeAddOp(v, OP_Null, 0, 0); */
/*       sqlite3VdbeAddOp(v, OP_Goto, 0, addr+7); */
/*       sqlite3VdbeOp3(v, OP_MakeRecord, 1, 0, &affinity, 1);   /1* addr + 4 *1/ */
/*       sqlite3VdbeAddOp(v, OP_Found, pExpr->iTable, addr+7); */
/*       sqlite3VdbeAddOp(v, OP_AddImm, -1, 0);                  /1* addr + 6 *1/ */

/*       break; */
/*     } */
/* #endif */
/*     case TK_BETWEEN: { */
/*       Expr *pLeft = pExpr->pLeft; */
/*       struct ExprList_item *pLItem = pExpr->pList->a; */
/*       Expr *pRight = pLItem->pExpr; */
/*       sqlite3ExprCode(pParse, pLeft); */
/*       sqlite3VdbeAddOp(v, OP_Dup, 0, 0); */
/*       sqlite3ExprCode(pParse, pRight); */
/*       codeCompare(pParse, pLeft, pRight, OP_Ge, 0, 0); */
/*       sqlite3VdbeAddOp(v, OP_Pull, 1, 0); */
/*       pLItem++; */
/*       pRight = pLItem->pExpr; */
/*       sqlite3ExprCode(pParse, pRight); */
/*       codeCompare(pParse, pLeft, pRight, OP_Le, 0, 0); */
/*       sqlite3VdbeAddOp(v, OP_And, 0, 0); */
/*       break; */
/*     } */
/*     case TK_UPLUS: */
/*     case TK_AS: { */
/*       sqlite3ExprCode(pParse, pExpr->pLeft); */
/*       stackChng = 0; */
/*       break; */
/*     } */
/*     case TK_CASE: { */
/*       int expr_end_label; */
/*       int jumpInst; */
/*       int nExpr; */
/*       int i; */
/*       ExprList *pEList; */
/*       struct ExprList_item *aListelem; */

/*       assert(pExpr->pList); */
/*       assert((pExpr->pList->nExpr % 2) == 0); */
/*       assert(pExpr->pList->nExpr > 0); */
/*       pEList = pExpr->pList; */
/*       aListelem = pEList->a; */
/*       nExpr = pEList->nExpr; */
/*       expr_end_label = sqlite3VdbeMakeLabel(v); */
/*       if( pExpr->pLeft ){ */
/*         sqlite3ExprCode(pParse, pExpr->pLeft); */
/*       } */
/*       for(i=0; i<nExpr; i=i+2){ */
/*         sqlite3ExprCode(pParse, aListelem[i].pExpr); */
/*         if( pExpr->pLeft ){ */
/*           sqlite3VdbeAddOp(v, OP_Dup, 1, 1); */
/*           jumpInst = codeCompare(pParse, pExpr->pLeft, aListelem[i].pExpr, */
/*                                  OP_Ne, 0, 1); */
/*           sqlite3VdbeAddOp(v, OP_Pop, 1, 0); */
/*         }else{ */
/*           jumpInst = sqlite3VdbeAddOp(v, OP_IfNot, 1, 0); */
/*         } */
/*         sqlite3ExprCode(pParse, aListelem[i+1].pExpr); */
/*         sqlite3VdbeAddOp(v, OP_Goto, 0, expr_end_label); */
/*         sqlite3VdbeJumpHere(v, jumpInst); */
/*       } */
/*       if( pExpr->pLeft ){ */
/*         sqlite3VdbeAddOp(v, OP_Pop, 1, 0); */
/*       } */
/*       if( pExpr->pRight ){ */
/*         sqlite3ExprCode(pParse, pExpr->pRight); */
/*       }else{ */
/*         sqlite3VdbeAddOp(v, OP_Null, 0, 0); */
/*       } */
/*       sqlite3VdbeResolveLabel(v, expr_end_label); */
/*       break; */
/*     } */
/* #ifndef SQLITE_OMIT_TRIGGER */
/*     case TK_RAISE: { */
/*       if( !pParse->trigStack ){ */
/*         sqlite3ErrorMsg(pParse, */
/*                        "RAISE() may only be used within a trigger-program"); */
/* 	return; */
/*       } */
/*       if( pExpr->iColumn!=OE_Ignore ){ */
/*          assert( pExpr->iColumn==OE_Rollback || */
/*                  pExpr->iColumn == OE_Abort || */
/*                  pExpr->iColumn == OE_Fail ); */
/*          sqlite3DequoteExpr(pExpr); */
/*          sqlite3VdbeOp3(v, OP_Halt, SQLITE_CONSTRAINT, pExpr->iColumn, */
/*                         (char*)pExpr->token.z, pExpr->token.n); */
/*       } else { */
/*          assert( pExpr->iColumn == OE_Ignore ); */
/*          sqlite3VdbeAddOp(v, OP_ContextPop, 0, 0); */
/*          sqlite3VdbeAddOp(v, OP_Goto, 0, pParse->trigStack->ignoreJump); */
/*          VdbeComment((v, "# raise(IGNORE)")); */
/*       } */
/*       stackChng = 0; */
/*       break; */
/*     } */
/* #endif */
/*   } */

/*   if( pParse->ckOffset ){ */
/*     pParse->ckOffset += stackChng; */
/*     assert( pParse->ckOffset ); */
/*   } */
/* } */

#ifndef SQLITE_OMIT_TRIGGER
/*
** Generate code that evalutes the given expression and leaves the result
** on the stack.  See also sqlite3ExprCode().
**
** This routine might also cache the result and modify the pExpr tree
** so that it will make use of the cached result on subsequent evaluations
** rather than evaluate the whole expression again.  Trivial expressions are
** not cached.  If the expression is cached, its result is stored in a
** memory location.
*/
/* void sqlite3ExprCodeAndCache(Parse *pParse, Expr *pExpr){ */
/*   Vdbe *v = pParse->pVdbe; */
/*   int iMem; */
/*   int addr1, addr2; */
/*   if( v==0 ) return; */
/*   addr1 = sqlite3VdbeCurrentAddr(v); */
/*   sqlite3ExprCode(pParse, pExpr); */
/*   addr2 = sqlite3VdbeCurrentAddr(v); */
/*   if( addr2>addr1+1 || sqlite3VdbeGetOp(v, addr1)->opcode==OP_Function ){ */
/*     iMem = pExpr->iTable = pParse->nMem++; */
/*     sqlite3VdbeAddOp(v, OP_MemStore, iMem, 0); */
/*     pExpr->op = TK_REGISTER; */
/*   } */
/* } */
#endif

/*
** Generate code that pushes the value of every element of the given
** expression list onto the stack.
**
** Return the number of elements pushed onto the stack.
*/
/* int sqlite3ExprCodeExprList( */
/*   Parse *pParse,     /1* Parsing context *1/ */
/*   ExprList *pList    /1* The expression list to be coded *1/ */
/* ){ */
/*   struct ExprList_item *pItem; */
/*   int i, n; */
/*   if( pList==0 ) return 0; */
/*   n = pList->nExpr; */
/*   for(pItem=pList->a, i=n; i>0; i--, pItem++){ */
/*     sqlite3ExprCode(pParse, pItem->pExpr); */
/*   } */
/*   return n; */
/* } */

/*
** Generate code for a boolean expression such that a jump is made
** to the label "dest" if the expression is true but execution
** continues straight thru if the expression is false.
**
** If the expression evaluates to NULL (neither true nor false), then
** take the jump if the jumpIfNull flag is true.
**
** This code depends on the fact that certain token values (ex: TK_EQ)
** are the same as opcode values (ex: OP_Eq) that implement the corresponding
** operation.  Special comments in vdbe.c and the mkopcodeh.awk script in
** the make process cause these values to align.  Assert()s in the code
** below verify that the numbers are aligned correctly.
*/
/* void sqlite3ExprIfTrue(Parse *pParse, Expr *pExpr, int dest, int jumpIfNull){ */
/*   Vdbe *v = pParse->pVdbe; */
/*   int op = 0; */
/*   int ckOffset = pParse->ckOffset; */
/*   if( v==0 || pExpr==0 ) return; */
/*   op = pExpr->op; */
/*   switch( op ){ */
/*     case TK_AND: { */
/*       int d2 = sqlite3VdbeMakeLabel(v); */
/*       sqlite3ExprIfFalse(pParse, pExpr->pLeft, d2, !jumpIfNull); */
/*       sqlite3ExprIfTrue(pParse, pExpr->pRight, dest, jumpIfNull); */
/*       sqlite3VdbeResolveLabel(v, d2); */
/*       break; */
/*     } */
/*     case TK_OR: { */
/*       sqlite3ExprIfTrue(pParse, pExpr->pLeft, dest, jumpIfNull); */
/*       sqlite3ExprIfTrue(pParse, pExpr->pRight, dest, jumpIfNull); */
/*       break; */
/*     } */
/*     case TK_NOT: { */
/*       sqlite3ExprIfFalse(pParse, pExpr->pLeft, dest, jumpIfNull); */
/*       break; */
/*     } */
/*     case TK_LT: */
/*     case TK_LE: */
/*     case TK_GT: */
/*     case TK_GE: */
/*     case TK_NE: */
/*     case TK_EQ: { */
/*       assert( TK_LT==OP_Lt ); */
/*       assert( TK_LE==OP_Le ); */
/*       assert( TK_GT==OP_Gt ); */
/*       assert( TK_GE==OP_Ge ); */
/*       assert( TK_EQ==OP_Eq ); */
/*       assert( TK_NE==OP_Ne ); */
/*       sqlite3ExprCode(pParse, pExpr->pLeft); */
/*       sqlite3ExprCode(pParse, pExpr->pRight); */
/*       codeCompare(pParse, pExpr->pLeft, pExpr->pRight, op, dest, jumpIfNull); */
/*       break; */
/*     } */
/*     case TK_ISNULL: */
/*     case TK_NOTNULL: { */
/*       assert( TK_ISNULL==OP_IsNull ); */
/*       assert( TK_NOTNULL==OP_NotNull ); */
/*       sqlite3ExprCode(pParse, pExpr->pLeft); */
/*       sqlite3VdbeAddOp(v, op, 1, dest); */
/*       break; */
/*     } */
/*     case TK_BETWEEN: { */
/*       /1* The expression "x BETWEEN y AND z" is implemented as: */
/*       ** */
/*       ** 1 IF (x < y) GOTO 3 */
/*       ** 2 IF (x <= z) GOTO <dest> */
/*       ** 3 ... */
/*       *1/ */
/*       int addr; */
/*       Expr *pLeft = pExpr->pLeft; */
/*       Expr *pRight = pExpr->pList->a[0].pExpr; */
/*       sqlite3ExprCode(pParse, pLeft); */
/*       sqlite3VdbeAddOp(v, OP_Dup, 0, 0); */
/*       sqlite3ExprCode(pParse, pRight); */
/*       addr = codeCompare(pParse, pLeft, pRight, OP_Lt, 0, !jumpIfNull); */

/*       pRight = pExpr->pList->a[1].pExpr; */
/*       sqlite3ExprCode(pParse, pRight); */
/*       codeCompare(pParse, pLeft, pRight, OP_Le, dest, jumpIfNull); */

/*       sqlite3VdbeAddOp(v, OP_Integer, 0, 0); */
/*       sqlite3VdbeJumpHere(v, addr); */
/*       sqlite3VdbeAddOp(v, OP_Pop, 1, 0); */
/*       break; */
/*     } */
/*     default: { */
/*       sqlite3ExprCode(pParse, pExpr); */
/*       sqlite3VdbeAddOp(v, OP_If, jumpIfNull, dest); */
/*       break; */
/*     } */
/*   } */
/*   pParse->ckOffset = ckOffset; */
/* } */

/*
** Generate code for a boolean expression such that a jump is made
** to the label "dest" if the expression is false but execution
** continues straight thru if the expression is true.
**
** If the expression evaluates to NULL (neither true nor false) then
** jump if jumpIfNull is true or fall through if jumpIfNull is false.
*/
/* void sqlite3ExprIfFalse(Parse *pParse, Expr *pExpr, int dest, int jumpIfNull){ */
/*   Vdbe *v = pParse->pVdbe; */
/*   int op = 0; */
/*   int ckOffset = pParse->ckOffset; */
/*   if( v==0 || pExpr==0 ) return; */

/*   /1* The value of pExpr->op and op are related as follows: */
/*   ** */
/*   **       pExpr->op            op */
/*   **       ---------          ---------- */
/*   **       TK_ISNULL          OP_NotNull */
/*   **       TK_NOTNULL         OP_IsNull */
/*   **       TK_NE              OP_Eq */
/*   **       TK_EQ              OP_Ne */
/*   **       TK_GT              OP_Le */
/*   **       TK_LE              OP_Gt */
/*   **       TK_GE              OP_Lt */
/*   **       TK_LT              OP_Ge */
/*   ** */
/*   ** For other values of pExpr->op, op is undefined and unused. */
/*   ** The value of TK_ and OP_ constants are arranged such that we */
/*   ** can compute the mapping above using the following expression. */
/*   ** Assert()s verify that the computation is correct. */
/*   *1/ */
/*   op = ((pExpr->op+(TK_ISNULL&1))^1)-(TK_ISNULL&1); */

/*   /1* Verify correct alignment of TK_ and OP_ constants */
/*   *1/ */
/*   assert( pExpr->op!=TK_ISNULL || op==OP_NotNull ); */
/*   assert( pExpr->op!=TK_NOTNULL || op==OP_IsNull ); */
/*   assert( pExpr->op!=TK_NE || op==OP_Eq ); */
/*   assert( pExpr->op!=TK_EQ || op==OP_Ne ); */
/*   assert( pExpr->op!=TK_LT || op==OP_Ge ); */
/*   assert( pExpr->op!=TK_LE || op==OP_Gt ); */
/*   assert( pExpr->op!=TK_GT || op==OP_Le ); */
/*   assert( pExpr->op!=TK_GE || op==OP_Lt ); */

/*   switch( pExpr->op ){ */
/*     case TK_AND: { */
/*       sqlite3ExprIfFalse(pParse, pExpr->pLeft, dest, jumpIfNull); */
/*       sqlite3ExprIfFalse(pParse, pExpr->pRight, dest, jumpIfNull); */
/*       break; */
/*     } */
/*     case TK_OR: { */
/*       int d2 = sqlite3VdbeMakeLabel(v); */
/*       sqlite3ExprIfTrue(pParse, pExpr->pLeft, d2, !jumpIfNull); */
/*       sqlite3ExprIfFalse(pParse, pExpr->pRight, dest, jumpIfNull); */
/*       sqlite3VdbeResolveLabel(v, d2); */
/*       break; */
/*     } */
/*     case TK_NOT: { */
/*       sqlite3ExprIfTrue(pParse, pExpr->pLeft, dest, jumpIfNull); */
/*       break; */
/*     } */
/*     case TK_LT: */
/*     case TK_LE: */
/*     case TK_GT: */
/*     case TK_GE: */
/*     case TK_NE: */
/*     case TK_EQ: { */
/*       sqlite3ExprCode(pParse, pExpr->pLeft); */
/*       sqlite3ExprCode(pParse, pExpr->pRight); */
/*       codeCompare(pParse, pExpr->pLeft, pExpr->pRight, op, dest, jumpIfNull); */
/*       break; */
/*     } */
/*     case TK_ISNULL: */
/*     case TK_NOTNULL: { */
/*       sqlite3ExprCode(pParse, pExpr->pLeft); */
/*       sqlite3VdbeAddOp(v, op, 1, dest); */
/*       break; */
/*     } */
/*     case TK_BETWEEN: { */
/*       /1* The expression is "x BETWEEN y AND z". It is implemented as: */
/*       ** */
/*       ** 1 IF (x >= y) GOTO 3 */
/*       ** 2 GOTO <dest> */
/*       ** 3 IF (x > z) GOTO <dest> */
/*       *1/ */
/*       int addr; */
/*       Expr *pLeft = pExpr->pLeft; */
/*       Expr *pRight = pExpr->pList->a[0].pExpr; */
/*       sqlite3ExprCode(pParse, pLeft); */
/*       sqlite3VdbeAddOp(v, OP_Dup, 0, 0); */
/*       sqlite3ExprCode(pParse, pRight); */
/*       addr = sqlite3VdbeCurrentAddr(v); */
/*       codeCompare(pParse, pLeft, pRight, OP_Ge, addr+3, !jumpIfNull); */

/*       sqlite3VdbeAddOp(v, OP_Pop, 1, 0); */
/*       sqlite3VdbeAddOp(v, OP_Goto, 0, dest); */
/*       pRight = pExpr->pList->a[1].pExpr; */
/*       sqlite3ExprCode(pParse, pRight); */
/*       codeCompare(pParse, pLeft, pRight, OP_Gt, dest, jumpIfNull); */
/*       break; */
/*     } */
/*     default: { */
/*       sqlite3ExprCode(pParse, pExpr); */
/*       sqlite3VdbeAddOp(v, OP_IfNot, jumpIfNull, dest); */
/*       break; */
/*     } */
/*   } */
/*   pParse->ckOffset = ckOffset; */
/* } */

/*
** Do a deep comparison of two expression trees.  Return TRUE (non-zero)
** if they are identical and return FALSE if they differ in any way.
*/
int sqlite3ExprCompare(Expr *pA, Expr *pB){
  int i;
  if( pA==0||pB==0 ){
    return pB==pA;
  }
  if( pA->op!=pB->op ) return 0;
  if( (pA->flags & EP_Distinct)!=(pB->flags & EP_Distinct) ) return 0;
  if( !sqlite3ExprCompare(pA->pLeft, pB->pLeft) ) return 0;
  if( !sqlite3ExprCompare(pA->pRight, pB->pRight) ) return 0;
  if( pA->pList ){
    if( pB->pList==0 ) return 0;
    if( pA->pList->nExpr!=pB->pList->nExpr ) return 0;
    for(i=0; i<pA->pList->nExpr; i++){
      if( !sqlite3ExprCompare(pA->pList->a[i].pExpr, pB->pList->a[i].pExpr) ){
        return 0;
      }
    }
  }else if( pB->pList ){
    return 0;
  }
  if( pA->pSelect || pB->pSelect ) return 0;
  if( pA->iTable!=pB->iTable || pA->iColumn!=pB->iColumn ) return 0;
  if( pA->token.z ){
    if( pB->token.z==0 ) return 0;
    if( pB->token.n!=pA->token.n ) return 0;
    if( sqlite3StrNICmp((char*)pA->token.z,(char*)pB->token.z,pB->token.n)!=0 ){
      return 0;
    }
  }
  return 1;
}


/*
** Add a new element to the pAggInfo->aCol[] array.  Return the index of
** the new element.  Return a negative number if malloc fails.
*/
static int addAggInfoColumn(AggInfo *pInfo){
  int i;
  i = sqlite3ArrayAllocate((void**)&pInfo->aCol, sizeof(pInfo->aCol[0]), 3);
  if( i<0 ){
    return -1;
  }
  return i;
}

/*
** Add a new element to the pAggInfo->aFunc[] array.  Return the index of
** the new element.  Return a negative number if malloc fails.
*/
static int addAggInfoFunc(AggInfo *pInfo){
  int i;
  i = sqlite3ArrayAllocate((void**)&pInfo->aFunc, sizeof(pInfo->aFunc[0]), 2);
  if( i<0 ){
    return -1;
  }
  return i;
}

/*
** This is an xFunc for walkExprTree() used to implement
** sqlite3ExprAnalyzeAggregates().  See sqlite3ExprAnalyzeAggregates
** for additional information.
**
** This routine analyzes the aggregate function at pExpr.
*/
/* static int analyzeAggregate(void *pArg, Expr *pExpr){ */
/*   int i; */
/*   NameContext *pNC = (NameContext *)pArg; */
/*   Parse *pParse = pNC->pParse; */
/*   SrcList *pSrcList = pNC->pSrcList; */
/*   AggInfo *pAggInfo = pNC->pAggInfo; */


/*   switch( pExpr->op ){ */
/*     case TK_COLUMN: { */
/*       /1* Check to see if the column is in one of the tables in the FROM */
/*       ** clause of the aggregate query *1/ */
/*       if( pSrcList ){ */
/*         struct SrcList_item *pItem = pSrcList->a; */
/*         for(i=0; i<pSrcList->nSrc; i++, pItem++){ */
/*           struct AggInfo_col *pCol; */
/*           if( pExpr->iTable==pItem->iCursor ){ */
/*             /1* If we reach this point, it means that pExpr refers to a table */
/*             ** that is in the FROM clause of the aggregate query. */
/*             ** */
/*             ** Make an entry for the column in pAggInfo->aCol[] if there */
/*             ** is not an entry there already. */
/*             *1/ */
/*             pCol = pAggInfo->aCol; */
/*             for(i=0; i<pAggInfo->nColumn; i++, pCol++){ */
/*               if( pCol->iTable==pExpr->iTable && */
/*                   pCol->iColumn==pExpr->iColumn ){ */
/*                 break; */
/*               } */
/*             } */
/*             if( i>=pAggInfo->nColumn && (i = addAggInfoColumn(pAggInfo))>=0 ){ */
/*               pCol = &pAggInfo->aCol[i]; */
/*               pCol->iTable = pExpr->iTable; */
/*               pCol->iColumn = pExpr->iColumn; */
/*               pCol->iMem = pParse->nMem++; */
/*               pCol->iSorterColumn = -1; */
/*               pCol->pExpr = pExpr; */
/*               if( pAggInfo->pGroupBy ){ */
/*                 int j, n; */
/*                 ExprList *pGB = pAggInfo->pGroupBy; */
/*                 struct ExprList_item *pTerm = pGB->a; */
/*                 n = pGB->nExpr; */
/*                 for(j=0; j<n; j++, pTerm++){ */
/*                   Expr *pE = pTerm->pExpr; */
/*                   if( pE->op==TK_COLUMN && pE->iTable==pExpr->iTable && */
/*                       pE->iColumn==pExpr->iColumn ){ */
/*                     pCol->iSorterColumn = j; */
/*                     break; */
/*                   } */
/*                 } */
/*               } */
/*               if( pCol->iSorterColumn<0 ){ */
/*                 pCol->iSorterColumn = pAggInfo->nSortingColumn++; */
/*               } */
/*             } */
/*             /1* There is now an entry for pExpr in pAggInfo->aCol[] (either */
/*             ** because it was there before or because we just created it). */
/*             ** Convert the pExpr to be a TK_AGG_COLUMN referring to that */
/*             ** pAggInfo->aCol[] entry. */
/*             *1/ */
/*             pExpr->pAggInfo = pAggInfo; */
/*             pExpr->op = TK_AGG_COLUMN; */
/*             pExpr->iAgg = i; */
/*             break; */
/*           } /1* endif pExpr->iTable==pItem->iCursor *1/ */
/*         } /1* end loop over pSrcList *1/ */
/*       } */
/*       return 1; */
/*     } */
/*     case TK_AGG_FUNCTION: { */
/*       /1* The pNC->nDepth==0 test causes aggregate functions in subqueries */
/*       ** to be ignored *1/ */
/*       if( pNC->nDepth==0 ){ */
/*         /1* Check to see if pExpr is a duplicate of another aggregate */
/*         ** function that is already in the pAggInfo structure */
/*         *1/ */
/*         struct AggInfo_func *pItem = pAggInfo->aFunc; */
/*         for(i=0; i<pAggInfo->nFunc; i++, pItem++){ */
/*           if( sqlite3ExprCompare(pItem->pExpr, pExpr) ){ */
/*             break; */
/*           } */
/*         } */
/*         if( i>=pAggInfo->nFunc ){ */
/*           /1* pExpr is original.  Make a new entry in pAggInfo->aFunc[] */
/*           *1/ */
/*           u8 enc = ENC(pParse->db); */
/*           i = addAggInfoFunc(pAggInfo); */
/*           if( i>=0 ){ */
/*             pItem = &pAggInfo->aFunc[i]; */
/*             pItem->pExpr = pExpr; */
/*             pItem->iMem = pParse->nMem++; */
/*             pItem->pFunc = sqlite3FindFunction(pParse->db, */
/*                    (char*)pExpr->token.z, pExpr->token.n, */
/*                    pExpr->pList ? pExpr->pList->nExpr : 0, enc, 0); */
/*             if( pExpr->flags & EP_Distinct ){ */
/*               pItem->iDistinct = pParse->nTab++; */
/*             }else{ */
/*               pItem->iDistinct = -1; */
/*             } */
/*           } */
/*         } */
/*         /1* Make pExpr point to the appropriate pAggInfo->aFunc[] entry */
/*         *1/ */
/*         pExpr->iAgg = i; */
/*         pExpr->pAggInfo = pAggInfo; */
/*         return 1; */
/*       } */
/*     } */
/*   } */

/*   /1* Recursively walk subqueries looking for TK_COLUMN nodes that need */
/*   ** to be changed to TK_AGG_COLUMN.  But increment nDepth so that */
/*   ** TK_AGG_FUNCTION nodes in subqueries will be unchanged. */
/*   *1/ */
/*   if( pExpr->pSelect ){ */
/*     pNC->nDepth++; */
/*     walkSelectExpr(pExpr->pSelect, analyzeAggregate, pNC); */
/*     pNC->nDepth--; */
/*   } */
/*   return 0; */
/* } */

/*
** Analyze the given expression looking for aggregate functions and
** for variables that need to be added to the pParse->aAgg[] array.
** Make additional entries to the pParse->aAgg[] array as necessary.
**
** This routine should only be called after the expression has been
** analyzed by sqlite3ExprResolveNames().
**
** If errors are seen, leave an error message in zErrMsg and return
** the number of errors.
*/
/* int sqlite3ExprAnalyzeAggregates(NameContext *pNC, Expr *pExpr){ */
/*   int nErr = pNC->pParse->nErr; */
/*   walkExprTree(pExpr, analyzeAggregate, pNC); */
/*   return pNC->pParse->nErr - nErr; */
/* } */

/*
** Call sqlite3ExprAnalyzeAggregates() for every expression in an
** expression list.  Return the number of errors.
**
** If an error is found, the analysis is cut short.
*/
/* int sqlite3ExprAnalyzeAggList(NameContext *pNC, ExprList *pList){ */
/*   struct ExprList_item *pItem; */
/*   int i; */
/*   int nErr = 0; */
/*   if( pList ){ */
/*     for(pItem=pList->a, i=0; nErr==0 && i<pList->nExpr; i++, pItem++){ */
/*       nErr += sqlite3ExprAnalyzeAggregates(pNC, pItem->pExpr); */
/*     } */
/*   } */
/*   return nErr; */
/* } */
